How to do raw mongodb operations in mongoose?

In Mongoose, while the library provides many convenient methods for interacting with MongoDB, there are times when you might need to perform native MongoDB operations. Mongoose offers several approaches to directly utilize native MongoDB operations.

1. Using the collection Method

The collection method allows you to access the native MongoDB collection object, enabling you to directly use native MongoDB methods. For example:

javascript
const mongoose = require('mongoose');

// Assume database connection is established

// Get the model
const User = mongoose.model('User', new mongoose.Schema({ name: String }));

// Use the native findOne method
User.collection.findOne({ name: 'John Doe' }, (err, user) => {
  if (err) {
    console.error('Query failed:', err);
  } else {
    console.log('Found user:', user);
  }
});

2. Using the aggregate Method

Although Mongoose has its own aggregate method, you can also use the native aggregation framework. The following example demonstrates how to perform native aggregation operations:

javascript
User.collection.aggregate([
  { $match: { name: 'John Doe' } },
  { $limit: 1 }
]).toArray((err, results) => {
  if (err) throw err;
  console.log(results);
});

3. Using the db Object

You can also access the underlying MongoDB database object through Mongoose's db object to perform more complex operations, such as transaction handling:

javascript
const db = mongoose.connection.db;

db.command({ ping: 1 }, (err, result) => {
  if (err) throw err;
  console.log('Ping result:', result);
});

Although Mongoose provides many high-level abstractions that simplify interaction with MongoDB, when performing complex or specific database operations, directly using native MongoDB operations is entirely feasible. These methods can help you maintain the convenience of Mongoose while flexibly leveraging MongoDB's powerful features, which is particularly useful for handling complex queries or performance optimization.